All‐hexahedral element meshing: automatic elimination of self‐intersecting dual lines

There has been some degree of success in all‐hexahedral meshing. Standard methods start with the object geometry defined by means of an all‐quadrilateral mesh, followed by the use of the combinatorial dual to the mesh in order to define the internal connectivities among elements. For all of the known methods using the dual concept, it is necessary to first prevent or eliminate self‐intersecting (SI) dual lines of the given quadrilateral mesh. The relevant features of SI lines are studied, giving a method to remove them, which avoids deforming the original geometry. Some examples of resulting meshes are shown where the current meshing method has been successfully applied. Copyright © 2002 John Wiley & Sons, Ltd.     

基于可寻址分支分配器的CATV收费系统

给出了一种基于可寻址分支分配器的ＣＡＴＶ收费管理系统设计方案，并着重介绍了系统的工作原理及可寻址分支分配器的设计。     

Nuclear transfer and cloning

Ultraviolet-induced erythema is now recognized as an important clinical marker for skin cancer risk. People with a history of repeated erythematous exposures to sunlight are more likely to develop both melanoma and nonmelanoma skin cancers. Is erythema the most important thing we need to be concerned about in terms of protecting the public from the harmful effects of sunlight? What do we know about UV-induced erythema, and why is it a powerful influence on skin cancer risk?     

A broadly cross-protective monoclonal antibody binding to Escherichia coli and Salmonella lipopolysaccharides

During the last decade, episodes of sepsis have increased and Escherichia coli has remained the most frequent clinical isolate. Lipopolysaccharides (LPS; endotoxin) are the major toxic and antigenic components of gram-negative bacteria and qualify as targets for therapeutic interventions. Molecules that neutralize the toxic effects of LPS are actively investigated. In this paper, we describe a murine monoclonal antibody (MAb; WN1 222-5), broadly cross-reactive and cross-protective for smooth (S)-form and rough (R)-form LPS. As shown in enzyme-linked immunosorbent assay and the passive hemolysis assay, WN1 222-5 binds to the five known E. coli core chemotypes, to Salmonella core, and to S-form LPS having these core structures. In immunoblots, it is shown to react with both the nonsubstituted core LPS and with LPS carrying O-side chains, indicating the exposure of the epitope in both S-form and R-form LPS. This MAb of the immunoglobulin G2a class is not lipid A reactive but binds to E. coli J5, an RcP+ mutant which carries an inner core structure common to many members of the family Enterobacteriaceae. Phosphate groups present in the inner core contribute to the epitope but are not essential for the binding of WN1 222-5 to complete core LPS. Cross-reactivity for clinical bacterial isolates is broad. WN1 222-5 binds to all E. coli clinical isolates tested so far (79 blood isolates, 80 urinary isolates, and 21 fecal isolates) and to some Citrobacter, Enterobacter, and Klebsiella isolates. This pattern of reactivity indicates that its binding epitope is widespread among members of the Enterobacteriaceae. WN1 222-5 exhibits biologically relevant activities. In vitro, it inhibits the Limulus amoebocyte lysate assay activity of S-form and R-form LPS in a dose-dependent manner and it neutralizes the LPS-induced release of clinically relevant monokines (interleukin 6 and tumor necrosis factor). In vivo, WN1 222-5 blocks endotoxin-induced pyrogenicity in rabbits and lethality in galactosamine-sensitized mice. The discovery of WN1 222-5 settles the long-lasting controversy over the existence of anti-core LPS MAbs with both cross-reactive and cross-protective activity, opening new possibilities for the immunotherapy of sepsis caused by gram-negative bacteria.     

Solution conformation of the Pseudomonas syringae MSU 16H phytotoxic lipodepsipeptide Pseudomycin A determined by computer simulations using distance geometry and molecular dynamics from NMR data

Pseudomycin A is a cyclic lipodepsinonapeptide phytotoxin produced by a strain of the plant pathogenic bacterium Pseudomonas syringae. Like other members of this family of bacterial metabolites, it is characterised by a fatty acylated cyclic peptide with mixed chirality and lactonic closure. Several biological activities of Pseudomycin A are lower than those found for some of its congeners, a difference which might depend on the diverse number and distribution of charged residues in the peptide moiety. Hence, it was of interest to investigate its conformation in solution. After the complete interpretation of the two-dimensional NMR spectra, NOE data were obtained and the structure was determined by computer simulations, applying distance geometry and molecular dynamics procedures. The conformation of the large ring of Pseudomycin A in solution includes three rigid structural regions interrupted by three short flexible regions that act as hinges. The overall three-dimensional structure of the cyclic moiety is similar to that of previously studied bioactive lipodepsinonapeptides produced by other pseudomonads.     

In vitro short-term response of human erythrocytes to implant materials used in maxillo-facial rigid internal fixation

A number of retinal proteins are phosphorylated by a variety of kinases, resulting in well-known regulatory effects. The identity and role of corresponding phosphatases is less clear. We simultaneously measured the activity of serine/ threonine protein phosphatases type 1, 2A and 2C in bovine retinae. The enzymes were classified according to substrate specificity, divalent cation requirement and the effect of phosphatase subtype-specific inhibitors. The total- and specific activity of phosphatase type 2A was prevalent. Type 2C was 10-fold less abundant. 80% of type 1 and 50% of type 2A and type 2C, respectively, were soluble. An economic purification scheme was developed. We demonstrated the presence of phosphatase isozymes 2Calpha and 2Cbeta in bovine rod outer segments by enzymatic analysis as well as immunological techniques. The results suggest a yet unknown role of phosphatase type 2C in phototransduction. On the other hand, the immense amount of protein phosphatases found to be soluble - therefore not associated with rod outer segment membranes - points towards participation of these enzymes in the process of visual transduction not considered thus far.     

新疆重质混合原油研制高等级道路沥青

对利用新疆重质混合原油生产的减压渣油作为基质沥青制备高等级道路沥青进行了研究。考察了低硫石蜡基原油（A）和含硫环烷-中间基原油（B）的掺炼比对基质沥青四组分组成的影响，减压渣油软化点与基质沥青四组分组成的关系，以及添加剂对改进沥青性质的作用。由此得出原油（B）的合适掺炼量，减压渣油软化点的控制范围和优化的生产工艺条件，调合出了符合GB／T18150—2000和JTGF40—2004要求的高等级道路沥青。     

SSRF储存环预研制铝合金真空室的机械加工

上海同步辐射装置（SSRF）储存环铝合金超高真空室已研制成功，该机加真空室的尺寸大、尺寸精度、形位公差及粗糙度要求极高，不同于常规的大型超高真空室。在预研件加工中，成功地解决了一系列问题，如光洁度提高困难，加工成型后变形大；加工尺寸和精度受环境温度影响较大等。本文详细阐述了储存环真空室材料和热处理状态的选择依据，为了保证尺寸精度和形位公差所采取的工艺措施，分析了粗糙度的形成机理和影响因素，从刀具材料、几何角度、切削参数、冷却液选型等多方面提出了解决办法。     

一种新型2×2 S0I热光开关

设计并制作了一种新型的SOI 2×2马赫一曾德（MZ）热光开关。这种光开关采用了深刻蚀结构的配对多模干涉耦合器，同时，为了保证单模传输和调制，在连接波导和调制臂区域采用了浅刻蚀结构。深刻蚀结构增强了多模干涉耦合器对光场的限制，有利于自映像质量的提高，从而减少了自映像损耗和不均衡度，同时也提高了制作容差。基于强限制配对干涉耦合器的新型热光开关，其插入损耗为-11．0dB，其中包括光纤波导耦合损耗4．3dB，上升和下降开关时间分别为3．5μs和8．8μs。